Stem cell populations constitute only a small percentage of the total number of cells, but are of immense interest because of their ability to repopulate the body. The longevity of stem cells and the dissemination of stem cell progeny are desirable characteristics. There is significant commercial interest in these methods because stem cells have a number of clinical uses. There is also medical interest in the use of stem cells as a vehicle for gene therapy.
Proteins and other cell surface markers found on stem cell and progenitor cell populations are useful in preparing reagents for the separation and isolation of these populations. Cell surface markers are also useful in the further characterization of these important cells.
Yin et al., U.S. Pat. No. 5,843,633, incorporated herein by reference, describes a monoclonal antibody called AC133, which binds to a surface marker glycoprotein on hematopoietic stem and progenitor cells. The AC133 antigen is a 5-transmembrane cell surface antigen with a molecular weight of 117 kDa. Expression of this antigen is highly tissue specific, and has been detected on a subset of hematopoietic progenitor cells derived from human bone marrow, fetal bone marrow and liver, cord blood, and adult peripheral blood. The subset of cells recognized by the AC133 antibody is CD34bright, and contains substantially all of the CFU-GM activity present in the CD34+ population, making AC133 useful as a reagent for isolating and characterizing human hematopoietic progenitor and stem cells.
However, surface markers specific to non-hematopoietic stem cells and progenitor cells, and particularly central nervous system neural stem cells and progenitor cells have not been identified. Further, the AC133 antibody has not been used in methods for identifying, isolating, or enriching for non-hematopoietic stem cells or progenitor cells, particularly central nervous system (CNS) neural stem cells and progenitor cells. There remains a need for tools, such as monoclonal antibodies that are useful in isolating and characterizing human non-hematopoietic progenitor and stem cells, and particularly central nervous system (CNS) neural stem cells and progenitor cells.